Provenance Trials of 5-year-old Casuarina junghuhniana at Dianbai,Guangdong,China

A provenance trial of Casuarina junghuhniana was established at Dianbai, Guangdong Province in southern China. All the 28 seedlots of seeds came from Australian Tree Seed Centre. A complete randomized block design was employed with 16 trees per plot and 4 replicates. From 1 to 5 years old, tree heights (H) and diameters at breast height (DBH) were measured, the single tree volume (V) and tree survival percentage (S) were calculated. The results at 5 years old provenances showed that there were significant differences in tree height, DBH and single tree volume among provenances, which indicated that those provenances were genetic variation in tree growth indexes. Provenance genetic variation coefficient (GCV) and broad heritability (H2) were estimated, GCV was 23.54 % in tree height, 35.78 % in DBH and 84.76 % in single tree volume, and H 2 were 28.87 % in tree height, 24.98 % in DBH and 21.21 % in single tree volume. Using H, DBH, V and S of 5 years old provenances, by Multiple Objective Strategic Decision Analysis method,the provenances were optimized and ranked. For the purpose of high timber yield in plantation, the selected provenance rate was 25 % of the total seedlots in the trials. Seven seedlots, 19240, 17877, 17878, 19491, 19489, 19490 and 13950, were screened out as better provenances. After selecting, the provenance genetic gains were 16.08 % in tree height, 22.73 % in DBH and 49.61 % in single tree volume.